<template>
  <el-menu
    :default-active="activeMenu"
    mode="horizontal"
    @select="handleSelect"
  >
    <template v-for="(item, index) in topMenus">
      <!-- 首页路由特殊处理：无论是否有子菜单，都作为普通菜单项 -->
      <el-menu-item :style="{'--theme': theme}" :index="item.path" :key="index" v-if="item.path === '/index' && index < visibleNumber"
        >{{ item.meta.title }}</el-menu-item
      >
      <!-- 其他有子菜单的项 -->
      <el-submenu :style="{'--theme': theme}" :index="item.path" :key="index" v-else-if="item.children && item.children.length > 0 && index < visibleNumber">
        <template slot="title">
          <span>{{ item.meta.title }}</span>
        </template>
        <template v-for="(child, childIndex) in item.children">
          <el-menu-item
            :index="resolvePath(item.path, child.path)"
            :key="childIndex"
            v-if="!child.hidden"
          >
            <svg-icon v-if="child.meta && child.meta.icon" :icon-class="child.meta.icon" />
            <span>{{ child.meta.title }}</span>
          </el-menu-item>
        </template>
      </el-submenu>
      <!-- 其他无子菜单的项 -->
      <el-menu-item :style="{'--theme': theme}" :index="item.path" :key="index" v-else-if="index < visibleNumber"
        >{{ item.meta.title }}</el-menu-item
      >
    </template>

    <!-- 顶部菜单超出数量折叠 -->
    <el-submenu :style="{'--theme': theme}" index="more" v-if="topMenus.length > visibleNumber">
      <template slot="title">更多菜单</template>
      <template v-for="(item, index) in topMenus">
        <!-- 折叠菜单中的首页路由特殊处理 -->
        <el-menu-item
          :index="item.path"
          :key="index"
          v-if="item.path === '/index' && index >= visibleNumber"
          >{{ item.meta.title }}</el-menu-item
        >
        <!-- 折叠菜单中的其他子菜单 -->
        <el-submenu :index="item.path + '_more'" :key="index" v-else-if="item.children && item.children.length > 0 && index >= visibleNumber">
          <template slot="title">
            <span>{{ item.meta.title }}</span>
          </template>
          <template v-for="(child, childIndex) in item.children">
            <el-menu-item
              :index="resolvePath(item.path, child.path)"
              :key="childIndex"
              v-if="!child.hidden"
            >
              <svg-icon v-if="child.meta && child.meta.icon" :icon-class="child.meta.icon" />
              <span>{{ child.meta.title }}</span>
            </el-menu-item>
          </template>
        </el-submenu>
        <!-- 折叠菜单中的其他普通项 -->
        <el-menu-item
          :index="item.path"
          :key="index"
          v-else-if="index >= visibleNumber"
          >{{ item.meta.title }}</el-menu-item
        >
      </template>
    </el-submenu>
  </el-menu>
</template>

<script>
import { constantRoutes } from "@/router";
import path from 'path';
import { isExternal } from '@/utils/validate';

// 隐藏侧边栏路由
const hideList = ['/user/profile'];

export default {
  data() {
    return {
      // 顶部栏初始数
      visibleNumber: 5,
      // 当前激活菜单的 index
      currentIndex: undefined
    };
  },
  computed: {
    theme() {
      return this.$store.state.settings.theme;
    },
    // 顶部显示菜单
    topMenus() {
      // 直接从constantRoutes中获取首页路由
      const indexMenu = constantRoutes.find(route => route.path === '/index') || null;
      let topMenus = [];

      this.routers.map((menu) => {
        if (menu.hidden !== true) {
          if (menu.path !== '/index') {
            if (menu.path === '/') {
              // 兼容顶部栏一级菜单内部跳转
              topMenus.push(menu.children[0]);
            } else {
              topMenus.push(menu);
            }
          }
        }
      });

      // 将首页路由放在最前面
      if (indexMenu) {
        topMenus.unshift(indexMenu);
      }

      return topMenus;
    },
    // 所有的路由信息
    routers() {
      return this.$store.state.permission.topbarRouters;
    },
    // 设置子路由
    childrenMenus() {
      var childrenMenus = [];
      this.routers.map((router) => {
        for (var item in router.children) {
          if (router.children[item].parentPath === undefined) {
            if(router.path === "/") {
              router.children[item].path = "/" + router.children[item].path;
            } else {
              if(!this.ishttp(router.children[item].path)) {
                router.children[item].path = router.path + "/" + router.children[item].path;
              }
            }
            router.children[item].parentPath = router.path;
          }
          childrenMenus.push(router.children[item]);
        }
      });
      return constantRoutes.concat(childrenMenus);
    },
    // 默认激活的菜单
    activeMenu() {
      const path = this.$route.path;
      let activePath = path;
      if (path !== undefined && path.lastIndexOf("/") > 0 && hideList.indexOf(path) === -1) {
        const tmpPath = path.substring(1, path.length);
        activePath = "/" + tmpPath.substring(0, tmpPath.indexOf("/"));
        if (!this.$route.meta.link) {
          // 当顶部导航启用时，始终隐藏侧边栏
          this.$store.dispatch('app/toggleSideBarHide', true);
        }
      } else if(!this.$route.children) {
        activePath = path;
        // 当顶部导航启用时，始终隐藏侧边栏
        this.$store.dispatch('app/toggleSideBarHide', true);
      }
      return activePath;
    }
  },
  beforeMount() {
    window.addEventListener('resize', this.setVisibleNumber)
  },
  beforeDestroy() {
    window.removeEventListener('resize', this.setVisibleNumber)
  },
  mounted() {
    // 初始加载时隐藏侧边栏
    if (this.$store.state.settings.topNav) {
      this.$store.dispatch('app/toggleSideBarHide', true);
    }
    this.setVisibleNumber();
  },
  methods: {
      // 检查是否为http链接
      ishttp(str) {
        return str.indexOf('http://') === 0 || str.indexOf('https://') === 0;
      },
      resolvePath(routePath, childPath) {
        if (isExternal(childPath)) {
          return childPath;
        }
        if (isExternal(routePath)) {
          return routePath;
        }
        return path.resolve(routePath, childPath);
      },
      // 根据宽度计算设置显示栏数
      setVisibleNumber() {
        const width = document.body.getBoundingClientRect().width / 3;
        this.visibleNumber = parseInt(width / 85);
      },
      // 菜单选择事件
      handleSelect(key) {
        this.currentIndex = key;
        const route = this.routers.find(item => item.path === key);
        if (this.ishttp(key)) {
          // http(s):// 路径新窗口打开
          window.open(key, "_blank");
        } else if (!route || !route.children) {
          // 没有子路由路径内部打开
          this.$router.push({ path: key });
          this.$store.dispatch('app/toggleSideBarHide', true);
        } else {
          // 显示左侧联动菜单
          this.activeRoutes(key);
          this.$store.dispatch('app/toggleSideBarHide', false);
        }
      },
      // 当前激活的路由
      activeRoutes(key) {
        var routes = [];
        if (this.childrenMenus && this.childrenMenus.length > 0) {
          this.childrenMenus.map((item) => {
            if (key == item.parentPath || (key == "index" && "" == item.path)) {
              routes.push(item);
            }
          });
        }
        if(routes.length > 0) {
          this.$store.commit("SET_SIDEBAR_ROUTERS", routes);
        } else {
          this.$store.dispatch('app/toggleSideBarHide', true);
        }
      }

  },
};
</script>

<style lang="scss">
.topmenu-container.el-menu--horizontal > .el-menu-item {
  float: left;
  height: 50px !important;
  line-height: 50px !important;
  color: #999093 !important;
  padding: 0 5px !important;
  margin: 0 10px !important;
}

.topmenu-container.el-menu--horizontal > .el-menu-item.is-active, .el-menu--horizontal > .el-submenu.is-active .el-submenu__title {
  border-bottom: 2px solid #{'var(--theme)'} !important;
  color: #303133;
}

/* submenu item */
.topmenu-container.el-menu--horizontal > .el-submenu .el-submenu__title {
  float: left;
  height: 50px !important;
  line-height: 50px !important;
  color: #999093 !important;
  padding: 0 5px !important;
  margin: 0 10px !important;
}
</style>
